kubernetes上部署Memcached高可用記錄

bawn 發(fā)布于2019-07-01 16:57 / 1905人閱讀

摘要：部署實現(xiàn)高可用常用的兩個工具連接多個，請求轉(zhuǎn)發(fā)單單，互為主輔結(jié)構(gòu)結(jié)構(gòu)主要部署步驟使用啟動個每個容器初始化腳本得到另一個節(jié)點的因為就兩個節(jié)點，不是就是判斷另一個節(jié)點的監(jiān)聽狀態(tài)如果在監(jiān)聽說明是主節(jié)點需要復(fù)制它，否則反之復(fù)制節(jié)點

部署Memcached

memcached實現(xiàn)高可用常用的兩個工具：
1）magent：連接多個memcached，請求轉(zhuǎn)發(fā)
2）repcached：單master單slave，互為主輔

magent+memcached結(jié)構(gòu)

repcache+memcached結(jié)構(gòu)

主要部署步驟(repcache+memcached) 使用statefulset啟動2個memcached

md-5c107eeae9fb1-0                  1/1       Running     0          59s
md-5c107eeae9fb1-1                  1/1       Running     0          49s

每個容器初始化腳本

#得到另一個節(jié)點的HOSTNAME(因為就兩個節(jié)點，不是0就是1)
PARTNER=${HOSTNAME##*-}
if [ "${PARTNER}" = "0" ]; then
        PARTNER=${MY_POD_NAME}-1
fi
if [ "${PARTNER}" = "1" ]; then
        PARTNER=${MY_POD_NAME}-0
fi

#判斷另一個節(jié)點的監(jiān)聽狀態(tài)(如果在監(jiān)聽說明是主節(jié)點需要復(fù)制它，否則反之)

測試
主備切換
//啟動主節(jié)點后狀態(tài)為Listen，設(shè)置同步端口為22222
root@md-5c107eeae9fb1-0:/# memcached -p 11211 -X 22222 -v -d -u root -m 512
root@md-5c107eeae9fb1-0:/# replication: listen
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:11211           0.0.0.0:*               LISTEN      260/memcached
tcp        0      0 0.0.0.0:22222           0.0.0.0:*               LISTEN      260/memcached
tcp6       0      0 :::11211                :::*                    LISTEN      260/memcached

//啟動復(fù)制節(jié)點，同樣設(shè)置同步端口為22222
root@md-5c107eeae9fb1-1:/# memcached -p 11211 -X 22222 -x md-5c107eeae9fb1-0.md-5c107eeae9fb1.itfarm3.svc.cluster.local -v -d -u root -m 512
root@md-5c107eeae9fb1-1:/# replication: connect (peer=10.244.5.50:22222)
replication: marugoto copying
replication: start

//從節(jié)點加入后，主節(jié)點狀態(tài)為accept并取消對22222的監(jiān)聽
root@md-5c107eeae9fb1-0:/# replication: listen
replication: accept
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:11211           0.0.0.0:*               LISTEN      263/memcached
tcp6       0      0 :::11211                :::*                    LISTEN      263/memcached

//kill掉主節(jié)點
root@md-5c107eeae9fb1-0:/# kill 263
replication: cleanup start
replication: close
root@md-5c107eeae9fb1-0:/# replication: cleanup complete

//此時從節(jié)點成Listen狀態(tài)，監(jiān)聽復(fù)制端口22222，等待加入
root@md-5c107eeae9fb1-1:/# replication: connect (peer=10.244.5.50:22222)
replication: marugoto copying
replication: start
replication: close
replication: listen
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:11211           0.0.0.0:*               LISTEN      258/memcached
tcp        0      0 0.0.0.0:22222           0.0.0.0:*               LISTEN      258/memcached
tcp6       0      0 :::11211                :::*                    LISTEN      258/memcached
高可用
//啟動2個節(jié)點（一主一備）
md-5c107eeae9fb1-0                  1/1       Running     0          59s
md-5c107eeae9fb1-1                  1/1       Running     0          49s

//在主節(jié)點中添加item
$ telnet md-5c107eeae9fb1-0.md-5c107eeae9fb1.itfarm3.svc.cluster.local 11211
Trying 10.244.4.162...
Connected to md-5c107eeae9fb1-0.md-5c107eeae9fb1.itfarm3.svc.cluster.local.
Escape character is "^]".
set name 0 0 8
zhangsan
STORED
quit
Connection closed by foreign host.

//從節(jié)點查看item
$ telnet md-5c107eeae9fb1-1.md-5c107eeae9fb1.itfarm3.svc.cluster.local 11211
Trying 10.244.3.176...
Connected to md-5c107eeae9fb1-1.md-5c107eeae9fb1.itfarm3.svc.cluster.local.
Escape character is "^]".
get name
VALUE name 0 8
zhangsan
END

//模擬故障
$ kubectl.exe delete po md-5c107eeae9fb1-0
pod "md-5c107eeae9fb1-0" deleted

//重啟后數(shù)據(jù)恢復(fù)
$ telnet md-5c107eeae9fb1-0.md-5c107eeae9fb1.itfarm3.svc.cluster.local 11211
Trying 10.244.4.162...
Connected to md-5c107eeae9fb1-0.md-5c107eeae9fb1.itfarm3.svc.cluster.local.
Escape character is "^]".
get name
VALUE name 0 8
zhangsan
END
部署sasl安全認(rèn)證的memcached

測試
//使用statefulset啟動N個memcached
md-5c11b67a6ae9b-0                  1/1       Running            0          1h
md-5c11b67a6ae9b-1                  1/1       Running            0          1h
md-5c11b67a6ae9b-2                  1/1       Running            0          1h
使用python連接memcached
$ python3
Python 3.5.2 (default, Nov 23 2017, 16:37:01)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import bmemcached
>>> client = bmemcached.Client(("md-5c11b67a6ae9b-ha:11211"), "md-5c11b67a6ae9b", "ZcUu1AVGbB3PnDzhxfOjRLJhatugwZBe")
>>> client.set("name", "zhangsan")
True
>>> client.get("name")
"zhangsan"
>>>
分布式存儲
使用無頭服務(wù)來區(qū)分多個memcache
#!/usr/bin/env python3
import bmemcached
client = bmemcached.Client(("md-5c11b67a6ae9b-0.md-5c11b67a6ae9b.itfarm3.svc.cluster.local:11211",
    "md-5c11b67a6ae9b-1.md-5c11b67a6ae9b.itfarm3.svc.cluster.local:11211",
    "md-5c11b67a6ae9b-1.md-5c11b67a6ae9b.itfarm3.svc.cluster.local:11211"), "md-5c11b67a6ae9b", "ZcUu1AVGbB3PnDzhxfOjRLJhatugwZBe")
print(client.set("name", "zhangsan"))
print(client.get("name"))
運行
$ python3 test.py
True
zhangsan
各客戶端連接開啟了sasl安全認(rèn)證的memcached方案